As its name suggests, a motion sensor detects and delivers motion information of an object to which it is attached. Among other things, motion information may include the linear acceleration and rotational movement of the object. This motion information often is critical for operation of various widely used items (e.g., an aircraft or a guided rocket). For example, an aircraft may be required to take-off at a specific pitch angle and acceleration. Accordingly, to meet those specific requirements, the aircraft may rely heavily upon its on board motion sensors.
For motion detection functionality in more than one dimension, some devices are considered to provide up to “six degrees of freedom.” Specifically, as known by those in the art, motion detecting devices having six degrees of freedom provide data relating to 1) linear acceleration along three orthogonal axes (i.e., the X-axis, Y-axis, and Z-axis), and 2) rotational movement about those three axes.
Currently available multiple degree of freedom motion detecting devices (also known as “inertial measurement units,” or “IMUs”), however, are relatively large. Specifically, many currently available motion detecting devices have a plurality of individual sensors (e.g., gyroscopes and/or accelerometers) stacked in different physical orientations on a circuit board. A motion detecting device having three degrees of freedom, for example, may have a circuit board with two attached accelerometers. One of the accelerometers may be a two dimensional accelerometer horizontally mounted on the face of the circuit board, while the other accelerometer may be a one dimensional accelerometer mounted to a daughterboard, which is vertically mounted to the circuit board. In other words, the one dimensional accelerometer may be mounted orthogonally to the circuit board. Use of this configuration on a single board thus often increases device size and complexity, which typically increases overall cost requirements.